Sample-supply apparatus with sample mixer



Oct. 22, 1963 A. FERRARI 3, 7

SAMPLE-SUPPLY APPARATUS WITH SAMPLE MIXER Filed March 8, 1961 2Sheets-Sheet 1 I INVENTOR. firmres firm/'1' ATTORNEY Oct. 22, 1963 A.FERRARI 3,107,536.

SAMPLE-SUPPLY APPARATUS WITH SAMPLE MIXER Filed March 8, 1961 2Sheets-Sheet 2 FIG. 5

l A 7,4 5 72 45 1 m ATTORNEY United States Patent 3,107,536 SARlPLE-SUPPLY APPARATUS WITH SAMPLE MIXER Andres Ferrari, Scarsdaie, N.Y.,assigns: to Teehnicon Instruments Corporation, Chauncey, N.Y., acorporation of New York Filed Mar. 8, 1961, Ser. No. 94,342 14 Claims;(Cl. 73-423) This invention relates to automatic liquid-analysisapparatus and more particularly to the sample-supply means for suchapparatus, said sample-supply means comprising a stepwise movableturn-table carrying a series of cups or other containers for the liquidsamples which are presented individually to an aspiration or othersuitable takeoif device for transmission of the samples in succession tothe analysis apparatus.

In the case of certain liquids which contain matter which may settleout, it is necessary or desirable to stir the liquid before or evenwhile the liquid sample is removed rfroin the cups by the take-oi?device. For example but without limitation, in the clinical chemicalanalysis of blood, hemoglobin determinations are made on whole bloodspecimens which must be well mixed and homogeneous when aspirated orotherwise withdrawn from the cups by the take-off device.

It is therefore an important object of the present invention to providemeans for thoroughly mixing the liquid samples in the sample cupscarried by the sample-supply means so that the liquid samples are eachin well mixed condition at the time of their removal from the cups bythe take-01f means.

Another object is to provide for the automatic movement of the stirringdevice into and out of certain of the cups during the rest periods ofthe turn-table of the sample-supply means.

Another object is to eliminate or to reduce to a tolerable degreecontamination of the sample liquids which might otherwise occur byreason of the use of the same stirrer for a series of different samples.

The above and other objects, features and advantages of the inventionwill be apparent from the following description of the presentlypreferred embodiment of the invention, considered in connection with theaccompanying illustrative drawings.

In the drawings:

FIG. 1 is a top plan view of sample-supply means embodying theinvention;

FIG. 2 is a side view, partly in section on the line 22 of FIG. 1,showing the take-off means and the stirring means in operative positionsand in retracted positions;

FIG. 3 is a. view on a large scale, partly in elevation and partly insection, on the line 3-3 of FIG. 2;

FIG. 4 is a top plan view of part of the sample-supply means, with partsbroken away or omitted for clarification of the illustration; and 7 FIG.is a sectional view on the line 55 of FIG. 4.

Referring now to the drawings in detail, the samplesupply means, brieflydescribed, comprises a carrier, here shown as a turn-table 10 which isintermittently turned by suitable mechanism disposed within a housing12, said mechanism being illustrated by FIGS. 4 and 5 and hereinaftermore particularly described. The turn-table cornprises a plate 16 whichcarries a series of removable cups 18 for the liquid samples, said cupsbeing isposed laterally of each other in a circular row. For thispurpose plate 16 is provided with a series of holes 20 and the cups havea peripheral shoulder 22 which. rests on the marginal edge of the platearound the opening through which the cup projects as shown by FIGS. 2and 3.

The take-ofii' device 24 and the mixer 26 are mounted on the housing 12in the position shown by FIG. 1 and comprise parts which are movable toand from the positions illustrated in full lines and in broken lines byFIG. 2 in timed relation to the step movement of the turntable so thatduring each rest period of the latter the take-off tube 28 of thetake-oil device and one or more stirrer members 3t) are moved into andout of the cups when the latter are positioned at the station of saidtake-off device and at the station or stations of the mixer 26. As hereshown (FIGS. 2 and 3), the mixer 26 comprises two stirrers 30, one forthe cup which is positioned immediately before the take-oif position;and one for the cup which is positioned at the take-off position, asillustrated by PEG. 3, it being noted that the turn-table 1-0 is movableclockwise, viewing FIG. 1. The stirrer provided for the cup at thetake-off position is operable to stir the liquid while it is beingwithdrawn from the cup and thus maintain the liquid previously stirredby the other stirrer in well mixed condition and prevents settling ofmatter from. the liquid at the take-off position. This is dminable andsometimes necessary in the case of liquids which contain matter whichwould otherwise settle out in a very short time, but ordinarily themixer need have only the stirrer for the cup next to the take-oftposition.

The stirrer comprises a metal spindle 32 which fits within apolyethylene tube 34. The lower end 36 of said tube extends a shortdistance below the lower end of the cornp'anion spindle and is flattenedto provide a paddle-like element to improve the stirring action. Theopposite side walls of the tube at the flattened portion may be heldtogether in flat condition by heat fusing them or in any other suitableWay. The polyethylene tubes 34 are substantially non-wettable and hencedo not carry sample liquid from one cup to another. The non-wettableproperty of polyethylene is thus valuable to the present invention.Stirrers 30 are rotated by (a miniature electric motor 38 the shaft ofwhich is connected to one of the spindles 32. When two stirrers areemployed, the second spindle is actuated by the gearing which comprisesthe driving gear 40, rotated by the motor, and the comp-anion drivengear 42"to which the second spindle is suitably secured for rotationthereby. The gears are mounted for rotation between the cover plates 44and 46 carried by the housing of motor 38. p

The mixer 26 is preferably mounted for movement to and from operativeand retracted positions as a unit with the movable part 48 of thetake-off device 24. Said part 48 is a tubular metal crook through whichthe takeoff tube 28 formed of polyethylene tubing extends for connectionto the pump of the analysis apparatus whereby the sample liquidisaspirated from the cup at the take-oif position. Said crook 48 ispivotally movable and is mounted for pivotal movement to and from thepositions illustrated by FIG. 2, as described in US. Patent No.

3,038,340, issued June 12,1962. As there described, the V crook is fixedto a rock shaft 50 mounted in a bearing bracket 52 on the top of housing1-2 laterally of the turntable. The mixer 26 is fixed to said rock shatt50 by clamping the mixer frame or bracket 54 to said shaft by acompanion clamp 56. A rod 58 tor actuatingthe shaft is fixed theretoandprojects into the housing 12 through an elongated opening 60 (-FIG.2) for actuation by the positioned in the path of rod 58 so that whenthe rock shaft 56 is turned to the ,position in which the take-01f tube28 and the stirrer rod 32 are in the cup, motor 38 is operated, and whenshaft 50 is turned in the opposite direction to withdraw tube 28 and thestirrer from the cup, rod 58 disengages contact member 64 whichthereupon moves by its own spring action to open the switch and therebyinterrupt the operation of the motor. Any other equivalent switchingdevice may be used, for example a mercury switch mounted on the bracket54 to tilt with the latter so that the switch is closed when the mixeris in the sample cup and opened when the mixer is Withdrawn from thesample cup.

The mechanism for turning the turn-table 10 and for eifecting thepivotal movements of rock shaft 50 is described in detail in the abovementioned US. patent which is owned by the assignee of my presentapplication. As more fully described in said US. patent, a Geneva gear66 is mounted on a shaft 63 which is secured to a plate 70 of housing12. A pinion gear 72 is mounted for rotation on shaft 68 and Geneva gear66 is secured to said pinion gear. Gear 72 is in mesh with anintermediate gear 74 which is in mesh with a driven gear 76 and saidgear 74 is secured to a drive shaft 78 to which the turntable 10 issecured for intermittent rotation.

The driver for Geneva gear 66 is constituted by a pin 80 which projectsupwardly from a set of stacked gears 82 which is part of a speed changemechanism operated by \the lever 84 shown in FIG. 4. An electric motor,not shown, turns a gear 86 which meshes with one of the stacked gears82, depending upon the vertical position of gear 86, as set by theoperation of lever 84, to drive pin 80 which drives the Geneva gear 66for intermittently rotating the turn-table.

The pivotal movements of the take-off tube are also effected by theoperation of pin 80. More specifically, a cam member 88 is pivotallymounted at 90, at one end thereof, and the free end of the cam member isinterconneoted by the tension spring 92 with the lower end of a pin 94which is secured to plate 70. A wire link 96 interconnects the free endof cam member 88 and the lower end of rod 58.

When cam member 88 is in the retracted (broken line) positionillustrated in FIG. 4, the take-cit tube 28 and the stirrer 32 arewithdrawn from the cups. Cam member 88 has an arcuate part 98, and withthe stacked gears rotating counterclockwise, as viewed in FIG. 4, itwill be seen that before pin 80 engages a slot in the Geneva gear 66 torotate table 10, the pin will first strike the cam member, which is inthe path of movement thereof, and pivot said cam member from the full tothe broken line position thereof, with the pin riding along the arcuateportion 98 during the period that it remains engaged in a slot in saidGeneva gear 66. When pin 80 disengages the slot of the Geneva gear, saidpin also disengages cam member 88 and the latter is thereupon moved toits full-line position by spring 92 and the take-01f tube and stirrerare inserted into the sample cups. These movements of cam member 88result in moving the takeoff tube and the stirrer into and out of thecups while the turn-table is stationary.

While I have shown and described the preferred embodiment of myinvention, it will be understood that the invention may be embodiedotherwise than as herein specifically illustrated or described, and thatcertain changes in the form and arrangement of parts and in the specificmanner of practicing the invention may be made without departing fromthe underlying idea or principles of this invention within the scope ofthe appended claims.

What is claimed is:

1. In a liquid-sample supply apparatus comprising an intermittentlymovable carrier for a series of liquid-sample containers and a take-offdevice movable in relation to said carrier during the rest periods ofthe carrier to position the take-off device for withdrawing the liquidsamples from said containers and'to pisition the take-oil? device out ofthe path of movement of said carrier after each take-off operation,means for mixing the liquid in said containers on the carrier, saidmixing means comprising a stirrer automatically movable into and out ofsaid containers during the rest periods of said carrier.

2. In a liquid-sample supply apparatus comprising an intermittentlymovable carrier for a series of liquid-sample contmers and a take-offdevice movable in relation to said carrier during the rest periods ofthe carrier to position the take-off device for withdrawing the liquidsamples from said containers and to position the take-off device out ofthe path of movement of said carrier after each take-off operation,means for mixing the liquid in said containers on the carrier, saidmixing means comprising a stirrer automatically movable into and out ofsaid containers concomitantly with the movements of said take-01f deviceduring the rest periods of said carrier.

3. In a liquid-sample supply apparatus comprising an intermittentlymovable carrier for a series of liquid-sample containers and a take-offdevice movable in relation to said carrier during the rest periods ofthe carrier to position the take-off device for withdrawing the liquidsamples from said containers and to position the take-off device out ofthe path of movement of said carrier after each take-off operation,means for mixing the liquid in said containers on the carrier, saidmixing means com.- prising a stirrer automatically movable into and outof said containers during the rest periods of said carrier, said stirrerbeing positioned in relation to said take-olf device and said carrier sothat said stirrer is operable in the container positioned next to andback of the container at the take-off position in the direction ofmovement of said carrier so that the liquid is stirred before thecontainer therefore is moved to the take-off position.

4. In a liquid-sample supply apparatus comprising an intermittentlymovable carrier for a series of liquid-sample containers and a take-offdevice movable in relation to said carrier during the rest periods ofthe carrier to position the take-off device for withdrawing the liquidsamples from said containers and to position the take-olt device out ofthe path of movement of said carrier after each take-off operation,means for mixing the liquid in said containers on the carrier, saidmixing means comprising a plurality of stirrers automatically movableinto ditierent containers, respectively, during the rest periods of thecarrier.

5. In a liquid-sample supply apparatus comprising an intermittentlymovable carrier for a series of liquid-sample containers and a take-offdevice movable in relation to said carrier during the rest periods ofthe carrier to position the take-oil device for withdrawing the liquidsamples from said containers and to position the take-oil. device out ofthe path of movement of said carrier after each take-off operation,means for mixing the liquid in said containers on the carrier, saidmixing means com prising a plurality of stirrers automatically movableinto diiferent containers, respectively, during the rest periods of thecarrier, one of said last-mentioned containers being in the take-offposition and another of said last-mentioned containers being next to andback of said take-off position in the direction of movement of saidcarrier whereby the same liquid is stirred before the container reachesthe take-0H position and is also stirred during the withdrawal of theliquid by the take-off device.

6. In a liquid-sample supply apparatus comprising an intermittentlymovable carrier for a series of liquid-sample containers and a take-01fdevice movable in relation to said carrier during the rest periods ofthe carrier to position the take-off device for withdrawing the liquidsamples from said containers and to position the take-oft device out ofthe path of movement of said carrier after each take-01f operation,means for mixing the liquid in said containers on the carrier, saidmixing means comprising a stirrer automatically movable into and out ofsaid containers during the rest periods of said carrier, said stirrerhaving a substantially non-wettable surface whereby to eliminate orreduce the carry-over of the liquid from one container to another.

7. In a liquid-sample supply apparatus comprising an intermittentlymovable carrier for a series of liquid-sample containers and a take-01fdevice movable in relation to said carrier during the rest periods ofthe carrier to position the take-off device for withdrawing the liquidsamples from said containers and to position the take-01f device out ofthe path of movement of said carrier after each take-off operation,means for mixing the liquid in said containers on the carrier, saidmixing means comprising a plurality of stirrers automatically movableinto different containers, respectively, during the rest periods of thecarrier, one of said last-mentioned containers being in the take-offposition and another of said last-mentioned containers being back ofsaid take-oil position in the direction of movement of said carrierwhereby the same liquid is stirred before the container reaches thetake-oft position and is also stirred during the withdrawal of theliquid by the take-oil device.

8. In a liquid-sample supply apparatus comprising an intermittentlymovable carrier for a series of liquid-sample containers and a take-offdevice movable in relation to said carrier during the rest periods ofthe carrier to position the take-off device for withdrawing the liquidsamples from said containers and to position the takeoff device out ofthe path of movement of said carrier after each take-01f operation,means for mixing the liquid in said containers on the carrier, saidmixing means comprising a stirrer automatically movable into and out ofsaid containers during the rest periods of said carrier, and meansautomatically operable to interrupt the operation of said stirrer uponthe withdrawal thereof from the container.

9. In a liquid-sample supply apparatus comprising an intermittentlymovable carrier for a series of liquid-sample containers and a take-ohdevice movable in relation to said carrier during the rest periods ofthe carrier to position the take-off device for withdrawing the liquidsamples from said containers and to position the take-off device out ofthe path of movement of said carrier after each take-off operation,means for mixing the liquid in said containers on the carrier, saidmixing means comprising a rotary stirrer automatically movable into andout of said containers during the rest periods of said carrier, anelectric motor for operating said stirrer, and means including a switchcontrolling the circuit of said motor operable to interrupt theoperation of said stirrer upon the withdrawal thereof from thecontainer.

10. In a liquid-sample supply apparatus comprising an intermittentlymovable carrier for a series of liquid-sample containers and a take-offdevice movable in relation to said carrier during the rest periods ofthe carrier to position the take-01f device for withdrawing the liquidsamples from said containers and to position the take-01f device out ofthe path of movemeit of said carrier after each take-01f operation,means for mixing the liquid in said containers on the carrier, saidmixing means comprising a rotary stirrer automatically movable into andout of said containers during the rest periods of said carrier, andmeans including an electric motor for operating said stirrer movable asa unit with the stirrer when the latter is moved into and out of thecontainers.

11. In a liquid-sample supply apparatus comprising an intermittentlymovable carrier for a series of liquid-sample containers and a take-offdevice movable in relation to said carrier during the rest periods ofthe carrier to position the take-oft device for withdrawing the liquidsamples from said containers and to position the tak oit device out ofthe path of movement of said carrier after each take-0E operation, meansfor mixing the liquid in said containers on the carrier, said mixingmeans comprising a stirrer automaticflly movable into and out of saidcontainers during the rest periods of said carrier, said stirrer beingmovable as a unit with said take-oil device to and from said positionsthereof.

12. In a liquid-sample supply apparatus comprising an intermittentlymovable carrier for a series of liquid-sample containers and a take-oftdevice movable in relation to said carrier during the rest periods ofthe carrier to position the takeoff device for Withdrawing the liquidsamples from said containers and to position the take-oil? device out ofthe path of movement of said carrier after each take oif operation,means for mixing the liquid in said containers on the carrier, saidmixing means come prising a rotary stirrer automatically movable intoand out of said containers during the rest periods of said carrier, saidstirrer being movable as a unit with said takeoff device to and fromsaid positions thereof, and means including an electric motor toroperating said stirrer movable as a unit with the stirrer when thelatter is moved into and out of the containers.

13. In a liquid-sample supply apparatus comprising an intermittentlymovable carrier for a series of liquid-sample containers and a take-0Edevice movable in relation to said carrier during the rest periods ofthe carrier to position the take-off device for withdrawing the liquidsamples from said containers and to position the takeofl? device out ofthe path of movement of said carrier after each take-off operation,means for mixing the liquid in said containers on the carrier, saidmixing means comprising a rotary stirrer automatically movable into andout of said containers during the rest periods of said carrier, saidstirrer being movable as a unit with said take-oil device to and fromsaid positions thereof, means including an electric motor for operatingsaid stirrer movable as a unit with the stirrer when the latter is movedinto and out of the containers, and means automatically operable tointerrupt the operation of said stirrer upon the withdrawal thereof fromthe container.

14. In a liquid-sample supply apparatus comprising an intermittentlymovable carrier for a series of liquid-sample containers and a take-0ftdevice movable in relation to said carrier during the rest periods ofthe carrier to position the take-cit device for withdrawing the liquidsamples from said containers and to position the take-oif device out ofthe path of movement of said carrier after each take-off operation,means for mixing the liquid in said containers on the carrier, saidmixing means comprising a rotary stirrer automatically movable into andout of said containers during the rest periods of said carrier, saidstirrer being movable as a unit with said takeofi device to and fromsaid positions thereof, an electric motor for operating said stirrer,and means including a switch controlling the circuit of said motoroperable to interrupt the operation of said stirrer upon the withdrawalthereof from the container.

References Cited in the file of this patent UNITED STATES PATENTS

1. IN A LIQUID-SAMPLE SUPPLY APPARATUS COMPRISING AN INTERMITTENTLYMOVABLE CARRIER FOR A SERIES OF LIQUID-SAMPLE CONTAINERS AND A TAKE-OFFDEVICE MOVABLE IN RELATION TO SAID CARRIER DURING THE REST PERIODS OFTHE CARRIER TO POSITION THE TAKE-OFF DEVICE FOR WITHDRAWING THE LIQUIDSAMPLES FROM SAID CONTAINERS AND TO PISITION THE TAKE-OFF DEVICE OUT OFTHE PATH OF MOVEMENT OF SAID CARRIER AFTEREACH TAKE-OFF OPERATION, MEANSFOR MIXING THE LIQUID IN SAID CONTAINERS ON THE CARRIER, SAID MIXINGMEANS COM-